FLOODS ON SYCAMORE ISLAND

One of the realities of the Sycamore Island Club is that from time to time, the whole place disappears under water. After all, the Island resides in the Potomac River's flood plain. In the great flood of 1936 (river height was 28 feet), the river washed away the large boathouse that contained all the member's canoes, and the club's clubhouse which had just seen years of restoration work done on it.

The current clubhouse, built using steel girders on the lower floor every 10 feet, has survived 7 serious floods since it was built shortly after the catastrophe of 1936.

The following year, in 1937, it survived a 23-foot flood, and 5 years later in 1942, it survived a 27-foot flood! 1955 recorded a 17.6-foot flood and in 1972, Hurricane Agnes drenched the watershed producing a 22-foot flood. In 1985 the clubhouse suffered an 18-foot flood and the freak snowmelt and rain combination in January 1996, produced a flood of 19 feet. Eight months later, a wet week followed by Hurricane Fran culminated in the second flood of 1996 which reached 17.8 feet.
The Floods of 1996
January snow melt and rain
Hurricane Fran
Hurricane Fran
January snow melt and rain Hurricane Fran

River Height Thresholds
The river's height is estimated to be about 5.5 feet when the water reaches the top of the ferry landing on the Sycamore Island side. The ferry itself becomes difficult to operate above 5 feet and by 6 feet is almost impossible. The ferry's pull-rope can be manually pulled up to clear the water at about 10 feet; after that it must be disconnected. About 10 feet is also estimated to be the height that the water wets the grass floor of the canoe shed. About 16 feet is estimated to be the height the river has to reach before it wets the floor of the clubhouse's lower floor.

Data Analysis
An analysis of the data below reveals that, on average, the river floods high enough to threaten the lower floor of the clubhouse once every 7 - 10 years. Also, again on average, the river floods high enough to threaten the lowest canoe rack about once or twice every year! The region's cooler months are also its wettest months, accounting for the preponderence of floods during that time of the year.

Because of the fickleness of the weather, some years see almost no high water while other years experience too much. The trends in the data show there were twice as many serious floods (over 9.5 feet) between 1935 and 1965 than from 1965 to 1995. But for ALL floods (over 6.5 feet), there were almost twice as many floods in the 1970s, 1980s and 1990s as there were in any of the 4 decades before them. The last 30 years of the 20th century saw unprecedented suburban growth around the Island and significant suburbanization of hundreds of square miles of land upstream on both sides of the river. (To see this area before much of it was developed, view the 1937 aerial photo.) It would appear that development is reducing the land's ability to retain water, producing more flash flooding on a routine basis. So far, any trend toward a greater number of larger floods is not yet statistically significant. 1998 was considered an El Nino year (wet in our region) while 1999 and 2000 were La Nina years (dry in our region).

Below is the statistical record of peak river stage height (in feet) at the Little Falls gauge since 1931 (these are only the peaks above 6 feet). For more information or other river statistics, visit the USGS web site at Little Falls. (1999 and 2000 data not currently available.)

Year    DateHeight
-------------------------- 
1931April 36.90
---------------------
1932February 69.40
March 308.56
May 1415.25
October 197.54
November 119.43
---------------------
1933January 289.39
March 167.87
March 229.42
April 1910.15
April 2212.80
May 117.54
August 2510.57
---------------------
1934September 187.80
December 213.50
---------------------
1935January 248.98
February 178.85
April 128.43
September 87.79
---------------------
1936January 58.42
January 118.08
February 1710.37
February 2714.69
March 1311.16
March 1928.10
April 88.18
---------------------
1937January 2410.50
February 117.42
February 2310.58
April 2823.30
August 2710.10
October 227.90
October 3015.62
---------------------
1938December 127.27
---------------------
1939February 19.05
February 512.60
March 28.43
April 199.42
---------------------
1940March 57.18
April 107.38
April 2211.29
June 29.46
---------------------
1941April 79.07
---------------------
1942May 188.15
May 2413.17
October 1726.88
December 3113.15
---------------------
1943February 89.31
March 167.73
April 229.75
May 228.69
---------------------
1944March 97.23
March 157.94
March 259.12
May 99.43
---------------------
1945March 18.88
March 98.02
August 18.05
September 2013.88
---------------------
1946June 49.47
---------------------
1947March 177.53
---------------------
1948February 1610.69
April 1610.69
December 68.17
December 189.89
---------------------
1949January 19.26
January 78.83
January 298.96
April 167.24
June 2013.00
July 158.30
July 1910.26
---------------------
1950February 310.01
March 258.59
May 207.56
November 269.93
December 613.85
December 912.48
---------------------
1951February 39.42
February 87.98
February 228.81
April 19.81
April 148.76
June 1512.09
---------------------
1952January 38.68
January 299.15
February 68.67
March 1311.95
March 257.70
April 2914.17
May 138.99
November 2313.76
December 138.17
---------------------
1953January 128.85
January 269.08
March 167.84
March 2611.44
---------------------
1954March 312.47
October 1713.30
---------------------
1955January 19.56
March 79.96
March 2311.47
June 108.78
August 159.02
August 2017.60
---------------------
1956February 88.90
March 169.92
April 910.46
July 2110.75
---------------------
1957February 1211.10
April 711.40
---------------------
1958March 110.18
March 2911.19
April 99.95
April 309.66
May 712.02
---------------------
1959June 49.61
---------------------
1960April 112.29
April 613.35
May 1013.66
May 308.65
---------------------
1961April 1810.37
February 2113.15
February 2712.23
March 268.48
April 1411.71
---------------------
1962March 111.05
March 1411.42
March 2313.43
April 148.78
---------------------
1963January 148.80
March 712.87
March 1511.64
March 2113.91
---------------------
1964January 278.88
March 611.85
April 228.33
May 111.59
---------------------
1965January 267.56
February 107.33
March 79.98
March 287.11
---------------------
1966February 159.04
March 36.85
May 36.93
---------------------
1967March 911.48
May 96.97
December 137.75
---------------------
1968February 27.16
March 188.71
---------------------
1969March 275.75
---------------------
1970April 39.34
April 167.75
April 267.62
July 117.21
November 147.16
December 258.20
---------------------
1971January 77.18
February 158.73
February 249.15
June 18.77
September 126.94
October 268.17
---------------------
1972June 2422.03
February 157.88
February 288.85
April 177.39
May 67.55
July 17.11
October 89.08
December 108.63
December 176.81
December 248.52
---------------------
1973February 48.26
April 67.04
April 107.38
April 298.91
October 306.76
December 237.14
December 2810.36
---------------------
1974January 136.99
June 47.55
---------------------
1975March 2112.23
April 277.05
May 66.83
September 2713.39
October 208.24
---------------------
1976January 39.59
October 1113.18
---------------------
1977March 157.18
March 246.46
April 78.64
November 97.60
December 36.49
---------------------
1978January 2810.47
March 1610.83
March 289.65
May 179.44
---------------------
1979January 269.66
February 2613.12
March 78.61
March 266.76
September 79.09
October 16.81
October 57.28
October 77.72
October 128.15
November 46.82
---------------------
1980January 166.47
March 237.42
April 27.19
April 117.07
April 176.91
May 27.96
May 237.42
---------------------
1981February 246.57
April 156.95
---------------------
1982February 57.41
February 196.75
February 226.71
March 187.60
March 227.93
June 158.91
---------------------
1983March 217.84
April 57.17
April 118.82
April 168.75
April 269.81
May 187.31
May 246.95
December 148.98
---------------------
1984February 1613.73
February 266.94
March 236.94
March 3010.74
April 59.95
April 177.04
April 247.25
November 306.54
---------------------
1985February 149.08
November 717.99
November 306.97
---------------------
1986February 217.96
March 1610.09
---------------------
1987March 47.02
April 68.58
April 1911.41
---------------------
1988January 217.10
April 96.57
May 89.15
May 198.56
May 209.83
May 257.55
---------------------
1989March 266.48
May 67.84
May 88.41
May 127.90
May 189.10
---------------------
1990May 317.24
October 146.97
October 258.94
---------------------
1991January 18.21
January 188.93
March 67.10
March 258.94
---------------------
1992April 249.07
December 127.50
December 206.60
---------------------
1993March 612.35
March 2510.16
April 39.91
April 127.18
April 1810.55
April 238.05
April 286.70
November 2910.09
December 79.05
---------------------
1994January 317.53
February 117.54
February 259.20
March 119.90
March 177.93
March 247.29
March 3010.37
April 26.91
April 156.95
May 108.24
---------------------
1995January 178.90
January 217.18
June 306.51
October 226.84
---------------------
1996January 2119.29
January 267.69
January 299.39
March 219.20
April 37.78
May 87.16
May 126.66
May 197.04
May 316.71
June 136.58
June 207.81
August 26.83
August 148.30
September 817.84
September 117.19
September 146.72
September 196.85
October 207.26
November 108.25
December 39.02
December 158.52
---------------------
1997March 57.89
November 99.49
---------------------
1998January 1010.43* Pictures
January 256.49
January 298.29
February 69.88
February 146.89
February 199.88
February 258.63
March 117.90
March 2210.79
April 116.56
April 218.25
May 107.44
---------------------
1999  
  
---------------------
2000  
  
---------------------
2001March 237.39
April 16.20
---------------------